Phenolic antioxidants have been used for many years to stabilize organic material against oxidative degradation. For example, 4,4'-methylenebis-(2,6-di-tert-butylphenol) is a commercial antioxidant. Other phenolic antioxidants containing methylene bridges are described in U.S. Pat. Nos. 3,026,264, 3,211,652 and 3,297,575.